1-154-859 - NASA/Oxford Science Archive/Heritage Images

Four moons of Jupiter, Io, Europa, Ganymede and Callisto, 1979. Four separate pictures of these moons sometimes known as the Galilean moons taken from Voyager 1. Two Voyager spacecraft were launched in 1977 to explore the planets in the outer solar system. Voyager 1 flew past Jupiter at 278,000 kilometres in March 1979 before flying on to Saturn.